Integrated circuits find application in many of today's consumer electronics, such as cell phones, video cameras, portable music players, printers, computers, calculators, automobiles, etc. Integrated circuits may include a combination of active devices, passive devices and their interconnections.
In some instances, integrated circuits may take the form of nonvolatile memory designed to store digital data in the form of an electrical charge. Uniquely, a nonvolatile memory charge remains in storage even after the power is turned off. Accordingly, the use of nonvolatile memory devices can be particularly advantageous for power saving applications or in applications where power can be interrupted.
Nonvolatile memory usually takes one of two forms, a stack-gate form or a split-gate form. Nonvolatile memory cells utilizing the stack-gate type structure typically employ a configuration where a control gate lies over a floating gate in a stack. A select gate may be positioned adjacent the stack. In conventional programming schemes, contacts are formed to the control gate and select gate, as well as to source/drain regions adjacent the stack gate structure.
As the current processing technology node continues to decrease, contact area on nonvolatile memory devices necessarily shrinks. With reduced contact area, contact resistance increases. Thus, there is a need to provide reliable contacts to nonvolatile memory devices with low contact resistance, such as with a resistivity of less than about 30 microhm centimeter (μΩ·cm). Such contacts may provide for integrated circuit exhibiting improved programming speed, while increasing the amount of information that can be stored in a defined area. Further, there is a need to provide methods for forming such contacts that do not damage or inhibit performance of logic and other memory device components, such as through the use of low temperature anneal processes.
Accordingly, it is desirable to provide integrated circuits having nickel silicide contacts. Further, it is desirable to provide integrated circuits having nonvolatile memory structures with improved contacts. Also, it is desirable to provide methods for fabricating integrated circuits with contacts formed with low temperature anneal processes. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.